Sugar-cane mill



Al g- 27, 1946- I A. M; HEWLETT 0 5 suem CANE MILL Filed March 28, 1944 IINVENTORJI ll flfleqzkif Patented Aug. 27, 1946 SUGAR-CANE MILL Allen M. Hewlett, Haina, Hamakua, Territory of Hawaii Application March 28, 1944, Serial No. 528,398

10 Claims. 1

The present invention relates to cane mills of the type in which a layer or blanket of the cane is fed between superposed rollers, and the invention relates more particularly to the means employed for facilitating the feed of sugarcane to the rollers and for assisting the drag of the rollers. v

If the sugar cane blanket is too bulky, mill choke and slippage occurs and. the capacity of the mill is reduced, and various means have been proposed to facilitate the feed of the blanket.

One object of the present invention is to provide new and improved means for easing the feed of sugar cane into the mill rolls, and for preventing mill chok and slippage.

In carrying out certain features of the present invention, a compressing member carried by a pendulous support, is reciprocably actuated into position to precompress the cane blanket While travelling with said blanket towards the mill opening. On each return stroke, the compressing member swings away from the nip of the rollers in preparation for the next compression stroke. This precompressing operation reduces the thickness of the feed blanket andat the same time, keeps it depressed below a certain level within the limits of the angle of nip, to render said blanket more acceptable to the mill rollers. This operation prevents mill choke and slippage, and increases the capacity of the mill.

Various other objects, features and advantages of the invention will be apparent from the folowing particular description, and from an inspection of the accompanying drawing, in which:

Fig. 1 is an end elevation somewhat diagrammatic of a sugar mill embodying the present invention;

Fig. 2 is airont elevation of the mill, the feeding means being omitted; and

Fig. 3 is a diagram showing the operational movement of the compressing member of the present invention.

The present invention is shown applied to an extraction mill of the well-known 3-roller type comprising an upper roller l supported in a pair of spaced end frame pieces II, and a, pair of lower rollers l2 and I3-also supported in said frame pieces and peripherally spaced from said upper roller. The sugar cane to be ground and compressed may, for example, be delivered in the form of a, blanket along a. trough l I to the mill by a conveyor I8 from a crusher which prepares the cane by shredding and crushing. This prepared cane or bagasse first passes through the opening I4 between the upper roller I0 and the first lower roller I2 where the juice is extracted, and then over a guide I9 and through the smaller opening l5 between the upper roller l0 and the second lower roller I3 for additional juice extraction. The rollers Ill, l2 and 13 may be supported in slidable bearings to permit adjustments of the relative peripheral positions of these rollers in a manner well-known in the art, and are driven at the ame peripheral speed, as for example, by means of the gearing I6.

For compacting the sugar cane before it enters the nip region of the rollers l0 and I2, there is provided in accordance With certain features of the present invention a, compressing member 20 in front of the upper roller l0 pendulously supported for free swinging movement and reciprocated up and down to compress, compact anddepress the cane blanket as it is fed to the rollers.

This compressing member 20 is desirably in the form of a substantially horizontal bar extending transversely with respect to the direction of feed of the cane blanket, and is shown as a wooden beam whichmay be about 2. "or 3" x 4" in crosssection, depending on the particular installation. The pendulous support for the compression member 20 desirably comprises a pair of connect-.

ing rods 2| freely suspended at their upper ends from respective cranks 22 fixed to a crank shaft 23, and connected at their lower ends to the compression bar 26, as for example, by bolts 24 passing through extensions 25 on said rods. The crank shaft 23 is supported at the upper end of the machine on bearings or pillow blocks 26 fixed responding bearing 26 bolted or otherwise secured thereto. r

The crank shaft 23 is desirably driven in the same direction as the upper roller ID, a for example, by a drive chain 33 passing over sprocket wheels 34 and 35 connected to and coaxial with the upper roller It and the crank shaft 23 re-,

spectively. The feed conveyor to the mill may also be driven from the roller ID from a sprocket wheel 36 onthe shaft of said roller.

- In the operation of thedevice-described, as the crank shaft 23 is rotated, the compression bar 20 is reciprocated up and down through connecting rods 2 I During the downward strok of the connecting rods 2|, the compression bar '20 forces the caneblanket downwardl 'towards the roller far. V,

12. As the cane blanket is drawn in between the being freely suspended from crank pins, swing towards the upper roll It), so that the compression bar 20 follows said blanket towards the first mill opening l4 while maintaining said blanket under compression. The compression mechanism is desirably so designed that the bottom of the compression bar 20 clears the surface of the bottom roller I2 by about 4 to 6 inches in downward limiting position of said bar. a

During the upward stroke of the connecting rods 2|, the bar 26 is lifted out of engagement with the cane blanket, and may slide up on the surfaceof the roller l0 and then be carried away from it, so that upon the next downward stroke of said connecting rods, the bar 26 will be dropped on the blanket at some distance from said top roller to again compress the blanket, as indicated diagrammatically in Fig. 3. If the blanket be very thiclethe bar may not leave it on the up movement and in that case the lower range of movement may be mainly up and down along the surface ofthe roller l0.

From the moment the cranks t2 reach the midpoint 'of their downward. stroke, th horizontal components of the motion of their crank pins is towards the roller i 0. Thus, the compression bar 23 is aided in its travel with the flow of the feed blanket upon which it is pressing, and aids in pushing the blanket towards the mill opening l4.

When the feed to the mill is too great, the sugar cane will. tend to pile upbehind the compression bar 25 and force it towards and usually against the surfaceof, the top rollerflfi. Thus, where a mill choke is impending, the compressio bar 29 is caused to operate at a point where it is most needed. e

In some installationsiit may be found necessary to provide some limitation to the outward swing of the rods 25, away from the upper mill roller if! to prevent the compression bar 26 from being thrust into the conveyor which feeds the mill. 'To limit this outward swing of the connecting rods 7 2 i, there may be provided, for example, across the conveyor trough, ahorizontal stop against which said rods strike when the swing outwardly too To preventthe connecting rods 2 I from swing ing inwardl towards the roller :0 so far as to cause thercompression bar to come down against said roller ina direction normal to the roller tangent, and thereby breaking, bending or 7 otherwise damaging the connecting rodsZL'the cranks 22 and/or the crank shaft 23, one'or more prongs or teeth ii] are connected to the compression bar Zll desirabl near. the foot of each con+ necting rod 2 I. With this construction, when the cranks 22 are in position most remote from the upper roller Hi, the prongs all will strike the roller surface and check the inward swing of the connecting rods 2L The prongs also serve to enter the blanket and insure the movement "of the bar 283 along with the blanket towards the rollers.

' By means of the construction of the present in vention, the feed blanket or layer is compacted,

. so that a thinner cane blanket results and easier feed of the blanket towards the mill opening is effected without prejudice to the juiceextraction.

This compressing and compacting of the feed blanket prior to its entry into the'nip region of the mill rollers Iii. and I2 prevents mill chokes, and reduces mill slippage.

The, mechanism of the present invention not only compresses the/sugar cane into a more com I end carried by and freely suspended from said 'motor.

blanket is depressed and restrained within the limits of the angleof nip of the mill.

The mechanism of the present invention is simple and inexpensive to manufacture, can be readily installed in existing mills without any substantial reconstruction of these mills, and can be also readily removed. The mechanism is also such as to permit the use of light parts without the danger of. breakage and requires no separate driving The speed of the mechanism automatically varies with the speed of the mill, maintaining a constant relative speed determined by the ratio of sprocket 34 to sprocket 35.

Although the invention is shown applied to a mill following the crusher "which prepares the. sugar cane by shredding or crushing, as far as certain aspects of the invention are. concerned,

the invention can also be applied to a crusher of e the 3 roller type.

As many changes can be made in the above ap-1 paratus, and many apparently widely different embodiments of this invention can be made without departing from the scope of the claims, it is intended thatall matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and notiin alimiting sense. What is claimed is: v 1. In a sugar cane mill of the type having opposed upper and lower extraction rollers, a cane compression memberextending above and transversely of the path of feed of the cane towards said rollers, rotatablemeans supporting said, compression member and permitting free swinging movement towards and from said upper roller, and means for alternately raising and lowering said compression membenwhereby'said compres: sion member comes down upon the feed cane at a distance from said upper roller to compress said cane, is carried by the cane towards the upper roller while said member is in compressive engagement with said cane, moves upwardly out of engagement with said cane when near said upper roller, and may freely swing back to its original position away from said upper roller in preparation for its next downward cane compressive phase.

2. In a sugar cane mill of the type having opv posed upper and lower juice extraction rollers, a cane feeding mechanism comprising a crank shaft, a crank device on said shaft, a substantially horizontal cane compression bar extending above and transversely of the path of feed or the cane, and connecting rod means having its upper crank device, and having its lower end connected to said bar and freeto swing towards andfrom' 9 said upper roller during rotation of said crank device. V V

3. In a sugar cane mill of the type having opposed upper and lower juice extraction rollers, a cane feeding mechanism comprising a cane com-. pression bar extending above and transversely of:

'the path'of feed of the'cane towards said rollers,

means freely suspending said compression bar for swinging movement towards and away from said- 7 upper. roller, stop means connected to said bar and adapted to engage saidupper roller tolimi-t swinging movement of said bartowards said roll-1 er, and means for alternately moving said compression member towards and away from the path of feed of said cane.

4. In a sugar cane mill of the type having opposed upper and lower juice extraction rollers,

,a cane feeding mechanism comprising a cane compression bar extending above and transversely of the path of feed or the cane towards said rollers, means suspending said compression bar for free swinging movement towards and away from said upper roller, prongs connected to said bar and adapted to enter the cane being fed to said rollers, and means for alternately moving said compression bar up and down, and towards and away from the path of feed of said cane.

5. In a sugar cane mill of the type having opposed upper and lower juice extraction rollers, a

cane feeding mechanism comprising a cane com-v pression bar extending above and transversely of the path of feed of the cane towards said rollers, a rotatable member, means freely suspending said compression bar from said member for swinging movement towards and away from said upper roller, whereby said bar is moved in a closed path and moved towards said roller when in the, lower part of its path of movement, and at a speed controlled by the rate of movement of the cane towards said roller, and the limit of said movement being eliected by the engagement of said bar with the upper roller.

6. Means for compressing cane being fed be-' tween upper and lower rollers, said means including a rotatable crank, a substantially horizontal cane compressing member and connecting means pivotally suspended on said crank and carrying said bar at the lower end thereof, whereby during each revolution of said crank said bar is alternately lowered into engagement with the cane and is carried thereby towards said roller, and is raised out of engagement with said cane when adjacent to and in contact with the upper roller, and is then free, to swing away from said upper roller.

7. In combination, a wind superposed cane crushing rollers, a cane compression member, a

rotatable support for said member and on which said member is freely suspended, whereby said member may swing back andforth directly above tently on the cane being delivered to said rollers and to compress said cane, said means including a cane compression member, a member rotatable in the same direction as the upper roller and pivotal connections eccentrically positioned on said rotatable member and freely suspending said compression member, whereby during the rotation of said rotatable member said compression member is raised adjacent to said upper roller and is then free to swing away from said upper roller, and is then lowered into engagement with the cane and at a distance from said upper roller,. and is then carried by the cane towards the upper roller.

9. An apparatus as defined in claim 8, in which there is provided means for rotating saidrotatable member at a peripheral speed substantially higher than the peripheral speed of said rollers.

10. In a sugar cane mill, the combination of a pair of superposed rollers, a crank positioned above said rollers and at the cane intake side thereof, a cane compression bar and means secured to said bar and pivotally suspended on said crank, whereby said bar is free to swing toward and from the upper roller, the position and radius of said crank being such that said bar engages said upper roller and is moved upwardly along the surface thereof, and may then swing away from said upper roller before being lowered into engagement with the cane. 1

ALLEN M. HEWLETT. 

